Portable speaker



FIG. 1 is an isometric view of a portable speaker, embodying my new design;

FIG. 2 is a front elevation view thereof;

FIG. 3 is a bottom plan view thereof;

FIG. 4 is a top plan view thereof;

FIG. 5 is a rear elevation view thereof the broken lines being shown for illustrative purposes only and form no part of the claimed design;

FIG. 6 is a left side elevation view thereof; and,

FIG. 7 is a right side elevation view thereof. 

CLAIM The ornamental design for a portable speaker, as shown and described. 